1. Field of the Invention
The invention relates generally to a seat frame reinforcement structure, and, more specifically to a seat frame reinforcement structure including a long reinforcing member that extends in the seat-width direction and that is provided between and connected to both side frames that constitute a framework of a seatback or a seat cushion.
2. Description of the Related Art
There is an existing seatback frame structure in which a reinforcing member is provided between and connected to both side frames to increase the side impact resistance of a seat. Japanese Patent Application Publication No. 2009-137348 (JP-A-2009-137348) describes a reinforcement structure in which a round pipe that serves as a reinforcing member is provided between and connected to both side frames of a seatback and a rod extends through the reinforcing member. The rod connects operation shafts of right and left reclining mechanisms to each other. According to JP-A-2009-137348, a framework structure of the seatback is reinforced by the round pipe used as the reinforcing member, and the rod is protected so as not to be exposed.
However, the double structure described in JP-A-2009-137348, in which the rod passes through the reinforcing member, increases the weight of a portion where reinforcing member and the rod are both provided.